[templar]

We're not gonna poke and prod anything with the technology to get here, unless they say it's okay.

Having the technology to get here does not mean they have the technology, or are carrying the technology, to defend themselves. Consider a Martian crossing the Rover. One good bite out of it and it's finished.

[Ender Wiggin]

Having the technology to get here does not mean they have the technology, or are carrying the technology, to defend themselves.
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Having the technology to get here means that they can at least maintain acceleration long enough to get up to ramscoop speed, or do in-system manoevers.

This same technology could be used to net a smallish asteroid and accelerate it into an Earth-impacting orbit. An effective and devastating weapon.

(Read Niven's Footfall, for a fiction scenario like that).

Speaking of Niven, he wrote a short story (The Fourth Profession)in which aliens came to us to trade, in a lightsail ship. Part of the deal was, we were to build a launching laser for them so they could continue their travels. Civilizations unable to build a bevawatt CW laser of the right wavelength were considered to be "animals", justifying the alien's backup plan for leaving the solar system: they had a gadget that would make the Sun go nova. This was foreshadoed in the story, the aliens arrived six years after a nova was detected here, from the same direction.